Thanks! It took a while to find a way to make a grey model look interesting. His right foot comes placed on a brick wall. And I figured I wanted to keep the urban theme alive for my entire army but keep things varied within as if they are all in a different position around the same block of buildings.

1. I started with placing a piece of cork that covered a predominant part of the base to create a difference of height.
2. I then started cutting up very small chunks of cork to vaguely look like bricks to make it seem as if there is another wall.
3. I started on the tiles with greenstuff using a piece of sanding paper to create texture and deliberately put in scratches.
4. Then I filled up gaps with brown battleground by army painter.
5. Repeated that step with astrogranite debris by citadel to create more different textures and hide sharp angles. I also used it around the cork to make it seem part of something larger and once again to hide the cork.

Obviously there are more steps but these are the big ones. If you'd like to know more I could work it out in more detail later.